Pressure control valve



Dec. 11, 1956 v. C. REDDY 2,773,491

PRESSURE CONTROL VALVE Filed Feb. 14. 1952 Zw 5%@ M7' #M A TTORNEY` United States Patent O PRESSURE CONTROL VALVE Virgin C. Reddy, Farmington, Mich., assignor to General Motors Corporation, a corporation of Delaware This invention relates to a iluid ilow regulating device for controlling the ilow of a tluid of varying pressure, in response to varying pressures of one or more other uids.

The invention is particularly well adapted and for purposes of illustration will be described and shown as applied to regulating the delivery of gas fuel to an internal combustion engine in accordance with the engine supercharger air delivery pressure and the engine lubricating oil pressure. The principal object of the invention is to improve such devices byl (l) providing a single unit having separate gas supply valves controlled by the respective air supercharging and lubricating oil pressures, (2) providing a gas flow control valve which is throttled to regulate the gas delivery pressure to the engine at a value slightly exceeding the engine air supply pressure, (3) providing such a device having a fluid pressure responsive means diiferentially responsive to both engine air and gas fuel supply 'pressures whereby the use of the device with relatively high gas pressures and relatively low supercharged air pressures is accommodated without an increase in the size of the device, and (4) providing such a device which is simple in construction and assembly and may therefore be made at relatively low cost.

The means by which these and other objects of the invention are attained will be more clearly understood from the following description of two illustrative embodiments thereof, having reference to the drawing, wherein:

Figure l is a fragmentary transverse sectional view through an internal combustion engine to which the device of the invention is particularly adapted for use.

Figure 2 is an assembly view of one form of a device constructed in accordance with the invention, showing parts broken away and in section and showing an engine oil pressure pump associated therewith.

Figure 3 is an enlarged fragmentary View similar to Figure 2, showing details of the valver and valve face seal.

Figure 4 is a view similar to Figure 3 but showing a modified form of Valve seal.

Referring now in detail to the drawings, and firstly to Figures l-3 thereof, the numeral 2 indicates generally a supercharged internal combustion engine having a working cylinder 4 in which is a piston 6driving a crankshaftv (not shown) by the usual connecting rod 8. Surrounding the cylinder 4 is shown an air box 10 receiving air under pressure from an engine driven supercharger blower 12. The connection 14 to the air box 10 represents means for subjecting the gas flow regulating device, now to be described, to the control of the pressure in the engine air box.

In Figure 2 there is shown a valve body in the form of a housing 16 having a gas inlet 18 and a gas outlet 20 at its opposite ends. The inlet 18 connects with a chamber 22 formed within the housing 16 and closed at its lower end by a plug 24. Fitted within the chamber 22 and resting on the plug 24 is an abutment and guide member 26 having a longitudinal passage 28 extending therethrough into which slidably intrudes the lower end of a valve stem 30 whose upper end carries a pad 32. The stem 30 is formed with a series of downwardly decreasing diameters providing upper and lower shoulders 34 and 36. The lower shoulder 36 is normally spaced above the abutment and guide member 26 as shown, which latter member serves to limit downward movement of the stem during operation of the device. Slidably tting the stern 30 intermediate the shoulders 34 and 36 is a valve assembly 38 comprising an annular upright cup-shaped member 40 in which is seated in nesting relation a similarly cup-shaped valve seal member 42 of soft resilient rubber or equivalent material and a flat washer 44. Urging this valve assembly 3S upwardly against the upper shoulder 34 on the valve stem is a compression spring 46 whose opposite ends bear against the members 40 and 26. The sides of the cup-shaped seal member 42 terminate at their upper extremities with a rounded sealing face 48 which abuts the lower face 50 of an annular valve seat member 52. The seat member 52 is secured in the upper part of the chamber 22 as by a press lit in a counterbore 54 which connects the chamber 22 with an upper gas chamber 56. A large central opening 58 in the valve seat member 52 surrounds the valve stern to accommodate passage of gas when the valve 38 is opened. A screen 60 surrounds the valve and extends between the upper end of the chamber 22 and the abutment member 26 to prevent entrance of foreign matter through the opening 5S, To prevent pressure build-up in the passage 28 below the valve stem, as might interfere with opening of the valve, the lower face of the abutment and guide member 26 is provided with a recess 62 which communicates with the passage 2S and has communication with the chamber 22 through the small bleed hole 64 provided in the member 26.

Connecting the upper gas chamber 56 with a second valve chamber 22 formed in the housing 16 is a gas passage or duct 66. Disposed in said chamber 22 are a valve assembly 38, spring 46, valve seat member 52', and valve stem 30 and their associated parts which are identical in all respects to those previously described with reference to the chamber 22. Similarly the chamber 22 connects with an upper gas chamber 56', and the latter 1n turn is connected to the outlet 20 by a duct 68.

The upper face 70 of the housing 16 has clamped thereto a exible diaphragm 72 which forms the upper wall of the upper gas chambers 56 and 56. Clamping this diaphragm 72 to the housing 16 is a plate-like member 74 having its undersurface formed with recesses 76 and 78 opposite and of substantially the same cross sectional area as the upper gas chambers 56 and 56. The upper face of the plate-like member 74 is also provided with a larger recess S0 which is centrally aligned with and connected to the upper gas chamber 56 by an opening 82. Covering this recess 86 and clamped to the upper face of the plate-like member surrounding the recess 8i) is a second flexible diaphragm S4. A spacer member 86 which is slidably guided in the opening 82 serves to separate and transmit thrust between the diaphragms 72 and 84. lh order to prevent any pressure* build-up in the recesses 76 and 80 from interfering with the transmission of thrust by the spacer member 86 there is provided a vent passage 83 in the plate-like member which connects the recess to atmosphere.

Clamping the plate-like member 74 and the diaphragms 72 and 84 to the valve body 16 is an upper housing 90. Within this upper housing 90 is an air chamber 92 whose lower end terminates at the lower face of the housing in an enlargement or recess 94 of the same cross sectional area as the upper recess 80 in the plate-like member 74. Held downwardly against the upper diaphragm 84 by the upper diaphragm a compression spring 96 is a shoe 98. The upper end of the spring 96 is retained by an abutment 100 which is centered and adjustably positioned in the chamber 92 by a set screw M12-having a threaded engagement with the upper end of the housing 90 and locked in place by a clamp nut 104. The chambers 92 and 56, together with recesses '76, 80 and 94 and opening 82, thus constitute portions of a cylinder which is divided by the double diaphragm (72 and S4) into an air compartment and a gas compartment. Similarly, the recess 78 and chamber 56 constitute oil and gas compartments of a cylinder divided by diaphragm 72.

The air box pressure connection 14 previously referred to communicates as shown in Figure 2 with the air chamber 92, thereby subjecting the upper side of the upper diaphragm 8f4 to the pressure in the air box 10 of the engine.

The engine lubricating system is supplied with oil under pressure from a suitable pump indicated at 106 in Figure 2. in accordance with conventional practice this pump is driven through suitable means (not shown) by the engine, however, this is not necessary to the present invention, as the pump 106 may be separately driven by an electric motor or the like. In any event, a connection such as shown at 108 in Figure 2 extends from the delivery side of the pump 106 into the recess 70 in order to subject the portion of the lower diaphragm 72 opposite the chamber 56 to the oil pump delivery pressure.

A suitable bracket 110 the valve body 16 serves to support the lating device on the engine 2.

In operation, engine air pressure developed in the air box 10 by the blower 1.2 and engine lubricating oil pressure developed in the pump delivery line 108, when the engine is running, are transmitted to the chambers 92 and recess 7 0, respectively. The air pressure thus created in the chamber 92, with the assistance of the spring 96, applies suicient force to the upper diaphragm 84 to move the valve stem 30 and its valve assembly 38 downwardly against the normally higher pressure of the gas fuel in the lower gas chamber 22 and the compressive force of the spring 46, thereby moving the valve seal 42 away from the valve seat face 50 and allowing the gas to flow therebetween and through the opening 58 into the upper gas chamber 56. The gas in this upper chamber 56 thereupon exerts a pressure against the lower diaphragm 72 tending to force the same upwardly in opposition to the air pressure in the air chamber 92, the spacer member serving to transmit these gas andy air pressures between the two diaphragms 72 and 84. Since the lower diaphragm 72 has a smaller area exposed to the gas pressure in the upper gas chamber 56 the pressure of this gas is insutlcient to overcome the air pressure in the chamber 92 acting against the larger exposed area of 04 and the force of the spring 96 46 to fully close the opening 58. A pressure balance is thus obtained dependent on variations of the gas and air pressures. Should the engine speed decrease with resultant decrease in air pressure in the air box 10, a corresponding decrease in the pressure in the air chamber 92 results in a further closing of the opening 5S and a decreased flow of gas fuel to the engine. The degree of opening ot the valve assembly 38 for a given pressure in the air chamber 92 (equivalent to a corresponding operating speed of the engine 2) is adinstable by increasing or decreasing the tension of the spring 96 through the means of the adjusting screw 102.

The gas fuel passing through the opening 58 is conducted through the duct 66 to the lower gas chamber 22 from which it is allowed to pass through the valve seat 52' to the duct 68 and out the outlet 20, provided the engine lubricating oil pump 106 is operating and delivering suicient pressure through the line 108. With sufficient pressure being thus` delivered by the oil pump the having bolts 112 extending into gas ow reguto permit the spring oil in the recess 78 exerts sufficient `force against the lower diaphragm 72 to move the valve assembly 38' downwardly from their positions as shown in Figure 2 to permit flow of the gas through the valve seat member 52',

1n Figure 4 is shown a modification of the valve assembly and seal differing somewhat from that of 38, 38 and 52, 52. The seal 120 in accordance with this moditication consists of a round 0 section ring disposed in an annular outwardly open groove 122 formed in the upper face of the valve member 124. As shown the groove 122 has a depth slightly greater than the diameter of the ring O section and the side walls 126 and 128 are in upwardly converging relation to each other so as to provide an entrance to the groove 122 which is slightly narrower in width than the 0 section diameter of the seal ring. in this manner the seal ring is retained in place in the groove 122, without the necessity of the previously described washer 44. The operation of the gas tiow regulating device with this modiiied form of valve and valve seal is substantially the same as that of the previous modication.

While only two specic embodiments of the invention have been described and shown it will be understood that various changes and alterations may be made without departing from the spirit or scope of the invention as is now to be claimed.

I claim:

l. ln a gas fuel ow regulating means for an engine having an air intake system including an engine driven blower and a lubricating system including an engine driven oil pump, said means including a valve housing having a gas inlet and a gas outlet, cylinders respectively associated with said inlet and outlet, a valve passage connecting said inlet with its associated cylinder, a duct in said housing having one end connected with said inlet associated cylinder, a valve passage connecting the other end of said duct with said outlet associated cylinder, said outlet being in communication with its associated cylinder` a valve seat and a passage closable valve in each said valve passage, elastic members supportedby said housing and urging the valves against their seats to ettect closure of said passages, stems carried by the respective valves and slidably supported by the housing, a pair of opposed flexible diaphragms dividing said inlet associated cylinder into two compartments, one of said pair of diaphragms having a smaller effective area than the other diaphragm of said pair and being connected to the stem of said inlet associated valve, the compartment adjacent said other diaphragm being adapted for connection to the delivery side of the engine blower, a thrust transmitting spacer between said pair of diaphragms, an elastic member supported by said inlet associated cylinder to cooperate with the blower delivery pressure to transmit thrust to said other diaphragm to open said inlet associated valve in opposition to said gas supply pressure and said first named elastic member, and a exible diaphragm in said outlet associated cylinder having one of its sides in abutment with the stem of said outlet associated valve, said outlet associated cylinder being adapted on the opposite side of its diaphragm for connection to the delivery side of the engine oil pump.

2. In a gas ow regulator for an engine having an air supply supercharger and a lubricating oil pressure pump, a pair of slidably mounted control valves in series in a gas passageway, one of said valves being movable to open position by a differential pressure diaphragm having one side subjected to the gas pressure existing in said passageway between the valves and its other side adapted lto be subjected to the air pressure supplied by the supercharger, the other of said valves being movable to open position by a diaphragm having one side subjected to the gas pressure beyond said other valve and its other side adapted to be subjected to the lubricating oil pressure supplied by the pump, spring members urging said valves 3. A fuel ow regulator and automatic cut-off devicel for an internal combustion engine supplied with air and lubricating oil under pressure, comprising fluid pressure responsive means adapted to be subjected to the pressure of said air, other fluid pressure responsive means adapted to be subjected to the pressure of said oil, means dening a fuel passage, two valves in series normally closing said passage, one of said valves being connected for movement to open position by said first named responsive means, the other of said valves being connected for movement to open position by said other responsive means, each of said responsive means being in communication with the pressure of said gas in said passage beyond the respective valve connected thereto.

4. The invention delined in claim 3, wherein said rst named responsive means has a substantially smaller area in communication with said gas pressure than is its area subjectable to said air pressure.

5. The invention defined in claim 4, together ywith resilient means engaging said first named responsive means and acting thereon in the valve opening direction.

References Cited in the le of this patent UNITED STATES PATENTS Frink Jan. 22, 1867 Popham et al. Aug. 9, 1904 Gish Oct. 5, 1920 Hilger Dec. 27, 1938 Shaw July 15, 1942 Yates et al Aug. 25, 1942 Carter et al Oct. 6, 1942 Ferguson Nov. 3, 1942 Smith July 2, 1946 Hoof Mar. 18, 194'.7 Ensign July 5, 1949 Heller Feb. 14, 1950 Hieger Jan. 9, 1951 Koplin et al Jan. 15, 1952 Slonneger June 10, 1952 Burns Oct. 28, 1952 Curran June 3l, 1953 

